The present invention generally relates to firearm projectiles. More specifically, the present invention relates to interaction between a firearm projectile and a rifle bore.
Some shooters of firearms prefer bullets machined from a solid material as opposed to jacketed bullets, especially for rifles. Gyroscopic stability problems are associated with jacketed bullets due to the core of the bullet not being located at the true axis of rotation of the bullet, as compared to precision machined solid bullets. Some firearms include rifling within the barrel of the firearm. Rifling is a series of grooves cut into inside diameter of the barrel. The remaining material between the grooves is knows as the lands. The lands are what remain between the grooves after the grooves are cut in the inside diameter of a blank barrel. Typically lead core, or jacketed bullets, are slightly undersize but when enough pressure is put behind them, they upset or swell somewhat to seal into the groove diameter of a barrel of a firearm. Groove diameter is the largest diameter inside the barrel of the firearm. That is why worn out barrels do not shoot well. The barrels get worn beyond what a jacketed bullet is capable of upsetting within to seal against the barrel. This may only be a few tenths of a thousandths but it is enough to have pressure escape around the bullet.
Machining monolithic bullets instead of forging bullets allows for maintaining a constant center of gravity. Unlike jacketed bullets, current solid bullets do not seal tightly in worn or even slightly worn rifle barrels due to the fact that the solid bullets do not upset or expand to seal the bullet into the rifle barrel grooves when fired. If the solid bullets are not “sealed” in the rifle grooves during firing, gasses escape around the bullet causing inaccuracies to be experience when using solid bullets in some guns. When there is no sealing between the solid bullet and the barrel there can also be loss of potential speed of the bullet as it leaves the barrel. Solid copper bullets do not upset to fill the groove diameter. If there is any wear in the barrel or if the barrel is made slightly oversize due to the manufacturing process, blow by is experienced using solid copper bullets. Blow by is where pressure escapes around the bullet. That is why people that have shot solid copper bullets in the past have not been able to shoot them consistently. Typically in shooting five solid copper bullets, you may get three or four with in a group and one or two that are not in the group of the other shots.
It is an object of the present invention to provide a solid bullet that can seal within a rifled barrel during firing.